Variable displacement drive



July 24, 1951 w. M. cuTLER ET Al. 2,561,344

VARIABLE DISPLACEMENT DRIVE Filed Dec. 17, 1948 5 Sheets-Sheet 1 nventoras Henry B. Green OLg/L July 24, 1951 w. M. cUTLl-:R ETAL 2,561,344

VARIABLE DISPLACEMENT DRIVE Filed neo. 17, 1948 s sheets-sheet 2 [nnen fans* Wallace Cu?! er Edwin S. Kan zL July 24, 1951 Filed DSC. 17, 1948 w. M. cUTLl-:R ETAL 2,561,344

VARIABLE DISPLACEMENT DRIVE 3 Sheets-Sheet 3 /n van tom; Wallace N. Cuer Edwin S. Kant Patented July 24, 1951 VARIABLE nisrLaoEMENT DRIVE Wallace M. Cutler, Gloucester, Henry B. Greenough, Beverly, and Edwin S. Kant, Melrose, Mass., assignors to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application December 17, 1948, Serial N0. 65,867

13 Claims. (Cl. 'M -571) This invention relates to mechanism for transmitting power and is illustrated as embodied in dynamically balanced variable displacement drives for operating nail drivers of a heel attaching machine and for vibrating a nail distributor which serves said machine. The nail distributor is fully disclosed in an application for United' States Letters Patent Serial No. 65,868 filed December 17, 1948, in the names of Wallace M. Cutler et al.

The present invention consists in the novel features hereinafter described, reference being had to the accompanying drawings which illustrate embodiments of the invention selected for the purpose of illustration, the invention being fully disclosed in the following description and claims.

In the accompanying drawings,

Fig. 1 is a side view of a portion of the abovementioned nail distributor which is described in l center of mass of a counterweight as the throw of the eccentric is varied from to 0 Fig. 4 is a section on line IV-IV of Fig. 2; Fig. 5 is a front View of a dynamically balanced variable displacement drive for use in a heel 'attaching machine; and

Figs. 6 and 7 are sections on lines VI-VI and vnvn of Fig. 5.

The invention is described with reference to 'an eccentric drive 20 (Figs. 1 and 2) for vibrating or oscillating a nail carrier 22 of a nail disvtributor 24 and also with reference to an eccentric drive 26 for operating nail driving mechanism (not shown) of a heel attaching machine. lThe nail distributor 24, including the eccentric drive thereof, shown herein, is disclosed in detail in said application Serial No. 65,868.

Referring to the nail distributor illustrated in Figs. 1 to 4, the carrier 22 is mounted upon four 4leaf springs 28 (Fig. 1) (only one shown) supported by a base (not shown) bolted to the abovementioned heel attaching machine, said carrier having mounted in it the eccentric drive 20 which is operatively connected by a connecting rod 30 or actuator to a heavy abutment or weight 32 (Fig. l) secured by bolts 34 to the lower ends of a pair of flexible leaf springs 36 (only one shown). The upper ends of the flexible leaf springs 36 are secured by bolts 38 to the carrier 22, the carrier being adapted to vibrate approximately horizontally, that is, in a direction indicated by reference numeral 40, as the eccentric drive 26 is rotated to cause nails (not shown) to travel in succession down guides or raceways 42 of the carrier. It is to be noted that, since the raceways 42 are inclined at an angle of only about 5 to the horizontal, the direction of displacement of the carrier 22 is approximately lengthwise of the guides, the maximum displacement of the carrier being approximately 1/8". As will be explained later, the displacement of the carrier 22 may be reduced from a maximum of l/8 in accordance with the length and/or style of the nail to be accommodated.

It is desirable that the carrier 22 move substantially horizontally only since displacement in any other direction, especially vertically, seriously interferes with the steady flow of nails down the raceways 42. With this considerationin View the eccentric drive 29 for Ioperating the connecting rod 35 is dynamically balanced, such balance being maintained automatically irrespective of the throw of the connecting rod, as will be explained later. In the illustrative construction the relative masses of the abutment 32 and the carrier 22 are such that during operation of the drive 20 the abutment has a displacement three times that of the carrier. n

The drive 2U comprises interfitting shafts 44 (Figs. 1, 2 andl3), 46 (Fig. 2) which are mounted for rotation in ball bearings 48, 50, respectively, mounted in the carrier 22. The shafts 44, 46 have eccentric portions 52, 54, the eccentric portion 52 having recesses 56 in which fit tongues 53 of the eccentric portions 54. Arranged at a side of the shaft opposite the eccentric portions 52, 54 and longitudinally offset from said portions are eccentric portions (Figs. 2 and 4), 62 (Fig. 2) which balance the combined eccentric vportions 52, 54. The eccentric portions 50, 62 may be described as being longitudinally olfset at opposite ends of the eccentric portions 52. 54 and as being offset circumferentially about the eccentric portions 52, 54. It will thus be apparent that the shafts 44, 46, including their eccentric portions 52, 60 and 54, 62, respectively, form in effect a single shaft which may be referred to as a driver and which is dynamically balanced. By forming separate shafts 44, 46 it is possible quickly and eifectively to assemble the shafts in vthe machine.

Mounted for angular adjustment upon the eccentric portions 52, 54, which are in effect a single eccentric portion and will be referred to as such, is an eccentric or eccentric sleeve or member 64 (Figs. 2 and 3) which has secured to it inner races 66 of a ball bearing 68,` outer races 1U of said bearing being secured to the connecting rod 30. The ball bearing 68, together with its inner and outer races 65, l0, form in effect, and will be considered, part of the connecting rod 30.

In order dynamically to balance the eccentric 54 and the adjacent half of the connecting. rod 3G, including its bearing SB", upon the drive shaft 44, 46, there are mounted upon the eccentric portions Sli, 2 of said shaft counterweights 72 (Figs. 2 and Li) which may be described as ring shaped. To vary the throw of the connecting rod and ccordingly the amount of horizontal displacement of the carrier 22, the eccentric Ei is initially adjusted upon the eccentric portions 5.2 54 of the shaft liti, it which are centered about a line 'I4 (Figs. 3 andv 3A) parallel to and spaced from an axis of' rotation 'iS of.' the shaft 4t, 46.

When the eccentric 54 has been angularly adjusted about the center line 'lfi of the eccentric portions 52, 54' to its position shown in Fig. 3, the connecting rod Si] has its maximum throw of about /g of an inch, said center line lll being parallel to and arranged midway between a center line 18 of. the eccentric W and the axis 'it of the `shaft |54, 4B, the center lines Tf1, i8 and the axis 75 lying'in a. common plane. rihe eccentric 54 is so constructed and .arranged that its center of mass is located. on the axis i8 which is equidistant from all points .cn the periphery of the eccentric ii. upon. which the inner races 5t of the ball bearings $3 are mounted. It will thus be clear that when the eccentric 6&3' is rotated clockwise 1.30u ,trom its .position shown in Fig. 3 upon the eccentric portions 52, 5d the 4locus or path of .the `center of mass of the eccentric 64 and the adjacent halfof the .connecting rod 3B on the .center line "i3 is a semicircle lll terminating` at the axis it. .the axis 76 .the connecting rod has no throw.

The shaft 54 fifi is rotated by a pulley Sii (Fig. 2), an .inner `part 82 of which is secured to the shaft. Formed in the 'inner part G2 of the pulley .SHI/are bores 84 'for receiving pins alii secured to an vouter part 3B or? the pulley which is slidable upon a boss Sii of said inner part, a nut S2 being threaded onto a.v split tapered extension gli' of said boss. Interposed' between 'the n ut 92 and the outer part .E13 of the pulley 8.1i is a spring Se which i serves to urge the outer part 88 oi the pulley Ytoward said inner part 82, thereby rendering effective a lV-Shap-ed' belt 512 Winch drives the pulley. The belt 9.8 is driven by a pulley (not shown) which is rotatably mounted directly below the pulley 86 upon a base (not shown) of the Adistributor, the .horizontal displacement of the carrier 22 with relation .to its base having no appreciable effect on the driving effort of the belt.

In .order to adjust the eccentric 64 into diierent angular positions' -upon the eccentricportions 52., 54' of the shafts $4, 611, said shafts are provided withv bores ist, |02 '(Fig. 2) in which fits a rod imi' 'againstwhich the split tapered extension '94 oi the vinner 'part 82 of the pulley .3d is forced. Secured in transverse -bores |398 ofv the rod IM and extending 'through .arcuate slots |08 in the eccentric portions 5i?, 54 Vand into va bore iill (Fig. 3) of the eccentric d'4 Aare pins i2 Which,

when the rod iii-4 Ais rotated, effect rotation of the A When the center line .iii vcoincides with s eccentric Si upon the eccentric portions 52, 54 of the shaft 4:5, 4t. Such adjustment is effected by placing a Wrench (not shown) in a transverse hole H (Fig. 2) at the outer end portion of the rod H36 and turning said Wrench, and accordingly the rod, about the axis. 16,. While holding the inner part .t2 of the pulley iii! stationary, the nut 92 being previously backed away on the split tapered extension Si@ of said inner part of the pulley to release the rod from the pulley.

llt will be apparent that adjustment of the eccentric 5t on the eccentric portions 52, i/l of the shaft iid, it, unless compensated for, will disturb the balance of the shaft. Accordingly, there are secured in 'cores it (Figs, 2 and 4) of the rod H34, pins H8 which extend through arcuate slots in the eccentric portions 66, t2 of the shaft '54, it and with a clearance of about seven thousandths of an inch into bores |22 oi the counter- Weights l2, the arrangement being such that the counterweghts are rotated upon their eccentric portions til, 62 in response to the above-described ftation 0i the rod |952 with. relation to the Shaft When the eccentric et is positioned as illus,- trated in Fig. 3 the counterweights l2, which may be considered collectively as a two-part counterweight and will be reierred to as such, are positioned upon their associated eccentric portions Eli, i? as shown in Fig. fl. When the parts. are thus positioned a center line Hifi through the eccentric. portions .60, 62 of the shaft 4t, 46 lies in a .plane which includes the axis i6 and the center lines 'ifi and le and is also parallel to said axis, and is positioned the same distance at one side of said axis as the center lline lil is positioned at the opposite side vof said axis.

The two-part counterweight 'i2 has a mass equal to that o1" the eccentric Si. plus the mass of an .adjacent half of the connecting rod, including its bear-ing, said counterweght being s0 constructed and arranged that its center of mass lies in a line which is parallel to,. and lies in a plane which includes, the axis l and the center lines T8, 'id and |24, the center lines i8. and |26 being .equally .spaced at opposite sides of the axis l5. The center .of mass of the two-part counter- Weight 'l2 also lies in a plane which is disposed at right angles to the axis i6 and includes the center oi mass of the eccentric ili and its adjacent half of the connecting rod 3D. It will. therefore, be clear that if the counterweights. 12 are rotated clockwise on their respective eccentrics G, 62 from their positions illustrated in Fig. 4, the locus or path of a center .of mass .of .the counterweights is a semicircle E23 the inner end of which coincides with the axis JS. When a line indicating an angle alpha of adjustment of the eccentric t4 Vand the two-.part counterweight 'i2 about their respective eccentric portions is rdrawn through the axis i6 intersecting vthe semic-irc'les 7-'9 and |28 which represent the loci Aof the centers of unbalanced Ymass -of the eccentric 64 and an. adjacent half of its connecting rod. .on the one hand andthe two-part counterweight on the other hand, said .centers of mass are. eqnidistant .from the .axis i6 irrespective Aof the angle of adjustment, .and since the masses are equal, the two unbalanced .masses will coun.- terbalanceeach other, thereby insuring `that' the eccentric drive 2li is at all times balanced. It will be noted that the angles alp-ha are vtvvicev as :great as the anglesbeta which indicate the angular distances through which centers of mass of the eccentricfandzthe counterbalance zswing with relation to the axis-16 of the driver.

In the above-mentioned heel attaching machine nail drivers (not shown) are raised in a nailing die (notv shown) of the machine by a vdriver head (not shown) reciprocated by a connecting rod or actuator |50 (Figs. 5, 6 and 7) the throw of which may be varied in'accordance with the lengths of nails to be driven into the work.

Mounted for rotation about an axis |52 in bearings |54 of a main frame |55 of the machine is a drive shaft |56 having formed integral with it a ange |58 to which a main casting |60 of a fly wheel |62 is secured by a plurality of bolts |64, |64Aj and |64B. The main casting |60 of the fly Wheel |62 is positioned upon the ilange |58 by dowels |66 which are permanently secured to the flange and pass through bores |68 of said casting. After positioning the fly wheel |62 upon the flange |58 and moving to its desired adjusted position a crank pin forming part of a crank |12 to elect the desired throw of the connecting rod |50, the bolts |64A, |64B which pass through bores |14 (Fig. 6) inthe main casting |60 of the fly wheel |62 and are threaded into the flange |58, are tightened to secure together the main casting and the various parts which, as will be hereinafter explained, are secured to the main ily wheel.

kAs above stated, it is desirable to vary the throw of the connecting rod |50 which is mounted upon a -projecting portion |5| of the crank pin |10 ofthe crank |12, said crank fitting rotatably in a cylindrical recess or bore |16 (Figs. 5 and 6) formed in the main casting |60 of the fly wheel |62, an axis |18 of the bore and a disk portion |80 ofthe crank being parallel to the axis of rotation |52 of the shaft |56 and being offset one-half of an inch from, and below, said axis |52. The crank pin |10 which has a shank portion fitting in a cylindrical bore |82 (Fig. Grof the disk vportion |80 of the eccentric member |12 is secured to said disk portion by a pair of screws |84 which are threaded into diagonally vdisposed recesses |86 of said disk portion and have Jtheir inner ends forced against a circular notch |66 formed in the shank portion of the crank pin. The crank pin |10 has formed in it a lubricant receiving recess |60 normally closed bya `screw |92. In order to reduce to a minimum the vibration of the machine the fly wheel |62 is dynamically balanced to compensate for the mass of the projecting portion |5| of the crank pin and the mass of the lower half or a predetermined adjacent part of the connecting rod |50. The projecting lportion |5| of the crank functions as an eccentric and may be referred to as such or as an eccentric member. It Will be apparent that whenever the positions of the crank |12 and accordingly the crank pin |10 are changed to vary the throw of the connecting rod |50 and therefore the stroke .ofthe nail drivers (not shown) of the machine, the balance of the fly wheel |62 and the shaft |56 upon which it is mounted is disturbed. Accordingly, there is provided an eccentric ring or counterweight |94 which is operatively connected for purposes of adjustment to the crank |12, the ring being rotated into different adjusted positions in an annular recess or bore |66 of the fly; Wheel casting |60 in timed relation with the angular adjustment of the eccentric member |5|' and at all times balancing the crank pin |10 and ,the lower.,half of the 'connecting rod |50.` l The annular recess |96 and accordingly the ring. |94 are centered about an axis which is parallel to, and is located one-half inch above, the axis of rotation |52 of the shaft |56. In order to insure that the ily Wheel with the exception of the projecting portion |5| of its crank pin |10 is dynamically balanced, the main casting of the fly wheel is bored at selected localities. j

The outer periphery of the diskportion |30 of the eccentric |12 and the inner periphery of the eccentric ring have teeth 200 and 202 formed on them and inserted in a two-well recess 204 in the 'main casting |60 of the fly wheel |62 are gears 206, 206 mounted upon a shaft 2| rotatable ina bore 2|2 (Fig. '1) of said casting. Also rotatable in a recess 2|4 (Fig. 5) of the main casting |60 of the fly wheel is a gear 2 |6 secured to a shaft. 2 l5 rotatable in a bore (not shown) of said casting. The teeth 200 of the eccentric member |12 mesh with the gear 2|6 which drives, through the gear 206, the shaft 210, and the gear 203 the eccentric ring |94, the construction and arrangement being such thatthe crank |12 and the ring |94 move degree for degree about their respective axes |18, |98. The fly wheel casting |66 in the vicinity of the gears is provided with a recess 220 and normally filling such recess is a cover plate 222 se-v cured by screws 224 to the main casting, said plate having formed in it an opening 226 for receiving a wrench (not shown) which is inserted in a hexagonal socket 228 at the forward end of the pin 2|0.

' Washers 230, 232A are interposed between heads of the screws |64A, |64B and the main casting |653 of the fly wheel |62, said washers 230 bearing against a step face 232 of the disk portion |80 of the crank |12 and the washers 230A bearing against the step face 234 of the eccentric ring |94. Preparatory to rotating the crank |12 vand the eccentric ring |94 into their .desired operating positions in the main casting |60 of the fly wheel |62 the screws Nilis., |6413 are loosened, the screw |64 remaining fastened.r A wrench-is then inserted in the hexagonal socket 226 in the shaft 2|@ and turned the proper amount to rotate the crank pin |10 into the, proper position to effect the desiredthrow ofthe connecting rod |56. When the-proper adjustment of the crank |12 has been effected the screws |64A, 164B are tightened, causing the washers 230, 232 to bear `with clamping pressure against the step faces 232, 234 to hold the crank |12 and the eccentric ring |94 in their proper adjusted positions.l

The eccentric ring |94 has removed from its peripheral portion a mass of material, providing a peripheral recess 260 which irrespective of the adjustment of the crank |12, is centered in radial alinement with an axis 238 of the crank pin |10 of the crank as shown in Fig. 5, a radial plane including the axis of rotation |52 of the shaft |56 and the axis 23S of said pin dividing the recess 236 inhalves.

The eccentric ring |94 is so constructed and arranged that its mass is substantially equal to the mass of the axially offset or projecting por tion |5| of the crank pin |10 plus the mass of the lower half of the connecting rod |50, a center of mass of the ring |94 lying in a line 240 which is parallel to the axis |52 and is displaced from and is parallel to the crank pin axis 233.

In Fig. 5 the crank |12 is shown as arranged for the greatest throw of the connecting rod |55, that is, four inches, the axis 233 of the crank pin 75 |10 being two inches below the axis of rotation allel :to .each other and ,are yequid'istant ifrcm the axis y|52 .at lopposite :sides thereof. above yexfl.plained the axes fl 18 and 158 vabout which y:the i.crank .|12 and the eccentric ring |913 are adjusted are parallel ,to Aeach other, lie in the plane just referred to and are .spacedone-half inch from .the z ,axis ,152, atopposite sides thereof.

A locus or ,path fof a center of massof the ring |94 Iduring .its adjustmcntfrom .maximum 1to 1min.- imum throw .of :the crank :|12 .is a semicrcle :245. I-.t .will `.thus be .clear `that any v'line ldraws/,ii .through .itheaxis of rotation fit-2.01- the shaft .|56 :and 1intcrsecting ythe circles .2:32, 246 will :be bisected-by the aXis |52. Since Ythe .centers .of .-mass .of the crank pin l'l and the .adjacent 'ha/lf ,of the vcon.-

,necting -rod I 50 on the one hand and the counter.- .Q1

weight |94 on Vthe .other .hand are ,displaced 180 Ifrom each Aother Aor fare v-positioned diametrically L.opposite each other about :the .axis ,|52 of the shaft |56 and have moment arms Whichare at all ,times equal, it .will 'be apparent that :the shaft .will

atall times .be balanced about its axis. -It will be noted that the center of mass of the `counter,- -weight |94 is offset slightly longitudinally of .the v:shaft |56 from the center of mass .of the crank: .pin |10 l,and .the adjacent half .of the .connecting rod |511. However, auch slight longitudinal -displacement of ,said centers ,of Amass .does not impair .for any lpractical purpose the dynamic .balance .of the shaft |56. .Since :moment arms ofthe -equalma-sses are equal and offset .180 about zthe axis |52 the shaft is .dynamically balanced.

VAHaving thus described the invention, what -We .claim .as new Vand desire to secure .by'Letters Patent .of ,the UnitedzStatesis:

.1. In a variable speed drive, a balanced driver rotatable vabout and balanced with lreference -to an axis, an .eccentric .member and a -counter-Weight vwhich are bodily rotatable about :said axis with the driver and have ytheir .centers .of mass arranged at opposite sides of and at equal distances from said axis and in a common plane including said axis, an actuator Awhich is carried by the eccentric member, :the masses of the counter- Weight on the one hand and the eccentric imember plus a j oredeterrnined adjacent portion of the actuator on -the other hand -being equal, and meansvfor Vinitially angularly adjusting the centers of `mass of said eccentric member and said eounterweigh-t degree for degree in the 'same d irection `about said .axis in circular paths which are of equal radius 'and the centers of which are equally spaced -from and are arranged at opposite sides of the axis of the driver to retain fthe drive balanced irrespective A.of the lthrow of the eccentric member and accordingly the displacement of the actuator.

2. lin a variable displacement drive, Aa frame, la. drive shaft which is mounted in said v'frame and has an eccentric portion, an eccentric sleeve mounted upon said eccentric portion of the shaft, .a connecting rod mounted upon said sleeve, said shaft having a pair of eccentric portions which lare offset longitudinally at opposite ends respectively of the first-named eccentric vportion and each of which is of the same size as, and offset 8 128.0" .circumferentially @of the .shaft .from, Ian adjacent half of fthe first-named Veccentric portion, counter-weights .mounted fupon said 2pair yof eccentric portions, means for adjusting fthe eccen- :tric sleeve into :different yoperative -fpositions circumferential-ly :on ythe iirst--named eccentric portion of the shaft to vary Athe throw vvof 'the foon- `l`nectingrod, and mechanism @responsive to 'move-.-

'ment o'f said means for :rotating the counterweights Linto different 4adjusted positions about -thefpair of eccentric portions of the :shaft upon vvwhich they are mounted in order ldynamically to balance the ydri-ve `shaft irrespective of the position ofthe sleeve u-pon the first-'named eccentric lportion land accordingly the throw of -the connecting rod.

13. -I-n -a variable displacement drive, fa balanced ndriver rotatable about an axis, an eccentric member which is mounted Vfor bodily rotation vwith the driver and has ja cylindrical surface Vin the axis of which lies the 4center -of mass of the-ejecentric membeip an actuator mounted *upon said cylindrical surface and having a displacement determined by Vthe throw of the eccentric Amember, -a counterweight mounted wfor bodily rotation with the driver, ythe centers of lmass of 'the eccentric member and the counterweight being arranged at opposite sides o f 'the vaxis of rotation of `the driver in a plane which Iincludes the 4axis of rotation of the driver, the mass of the eccenltric member plus .the mass of a `prede'termined adjacent part or the actuator times l.the distance from the axis of .the driver to the axis in .which said center vof mass of the eccentric lies `being substantially equal `to the mass of the .counterweight times the distance of `the center of 'mass tof -said counterweight from the axis of rotation of ,the driver, means for angularly radjusting `the eccentric member and the counterweight with relation to said driver about axes, respectively, which are parallel to the axis of rotation of the driver and are arranged at diametrically opposite sides of the axis of the driver to maintain the eccentric member and actuator forces act- I ing thereon, on the one hand, and the counterweight, on the other hand, in their 4above-mentioned balanced relation 'irrespective vof ythe 'setting vor the eccentric member 'and accordingly of fthe actuator, jand'meansfor securing vthe 'eccentric member and the counterweight 'for bodily movement with the driver and for releasing the eccentric member and countervveight for angular adjustment vupon the driver about their respective axes.

y4. In a lvariable displacement drive, a balanced driver rotatable about an axis, an eccentric vinember which is mounted for initial angular adjustment --upon said driver and is `bodily rotatable with the driver, said eccentric being initially adjustable into different angular positions upon the driver about an axis parallel to and spa-ced from the a-xis of 'the driver to vary the throw of the eccentric member, a 'counterweig-ht Awhich is 'bodily .rotatable with the driver and is mounted for initial angular adjustment upon the driver about `an axis which vis parallel to and is spaced from the axis of the driver and `which offset 180 about the driver axis -from the axis about which the eccentric member is adjusted, mechanism for securing the eccentric vmember and the counterweightgfor bod-ily movement with the driver and for releasing the eccentric member and the counterweight f or said initial angular adjustment upon the driver, and means for simultaneously moving the eccentric member and Vthe counterweight degree for degree about the axis of rotation of the driver with their centers of mass moving equal distances in opposite directions radially of the axis of said driver.

5. In a variable displacement drive, a driver rotatable and balanced about an axis, an eccentric member which is bodily rotatable With the driver and is initially adjustable on the driver into different operative positions about an axis which is parallel to and is spaced from the axis of rotation of the driver, a counterweight which is bodily rotatable with the driver and is initially adjustable into different operative positions on the driver about an axis which is parallel to, and lies in a, plane including, the axis of rotation of the driver and the axis about which the eccentric member is adjusted, the axes about which the eccentric member and the counterweight are adjusted on the driver being positioned equal distances at diametrically opposite sides of the axis of the driver, and means for initially adjusting the eccentric member and the counterweight degree for degree in the same direction about their respective axes and accordingly about the axis of the driver and for simultaneously therewith moving the centers of mass of the eccentric member and the counterweight which centers are diametrically arranged at equal distances at opposite sides of the axis of the driver equal-distances toward or away from the axis of the driver.

6. In a variable displacement drive, a driver rotatable about an axis, an eccentric member which is rotatable with said driver and is adjustable into'dilferent operative positions with relation to said driver about an axis which is parallel to and is offset at one side of the axis of rotation of said driver, a connecting rod, said eccentric member having a cylindrical periphery upon which the connecting rod is mounted and which is centered about an axis arranged parallel to the axis of rotation of said driver the axis of said cylindrical periphery including a center of mass of the eccentric member, a ring-shaped counterweight which is rotatable with the driver and is adjustable into different operative positions on the driver about an axis which is parallel to and lies in a plane including the axis of rotation of the driver and the axis about which the eccentric member is adjusted, the axes about which the eccentric member and the counterweight are adjusted relatively to said driver being positioned at equal distances at opposite sides of the axis of rotation of the said driver, said countervveight having a mass Which is equal to the mass of the eccentric member plus the mass of an adjacent half of the connecting rod and which is oiset 180 about the axis of rotation of said driver from the axis of the periphery of the eccentric member and has its center of mass located the same distance from the axis of rotation of the driver that the axis of the periphery of the eccentric member is located from the axis of rotation of the driver, and means for simultaneously adjusting the eccentric member and the counterweight, degree for degree, in the same direction about their respective axes of adjustment to insure that the driver shall be balanced irrespective of the adjustment and accordingly the throw of the eccentric member.

7. In a variable displacement drive, a powered shaft rotatable about an axis, a fly wheel secured to the shaft, a member rotatable with the fly wheel and adjustable into different operative positions with relation to the fly wheel about an axis which is parallel to and is offset at one side of the axis of rotation of the shaft, a crank pin which is secured to said member and has an axis, a connecting rod mounted upon said crank pin, and a counterweight which is rotatable with the ily wheel and is initially adjustable With relation to said fly wheel about an axis which is parallel to the axis of rotation of the shaft, is arranged in a plane including said other two axes and is offset laterally from the axis of rotation of the shaft at a side of the shaft axis opposite the axis about which said member is adjustable, the axes about which the crank pin and the counterweight are adjustable relatively to the ily wheel being positioned at equal distances from the axis of rotation of the shaft, said counterweight having a mass which is equal to the combined masses of the crank pin and an adjacent half of the connecting rod, the center of mass of the counterweight and the axis of the crank pin being positioned the same distance from the axis of rotation of the shaft and being offset circumferentially of said shaft from one another.

8. In a variable displacement drive, a driven shaft rotatable about an axis, a fly wheel secured to the shaft, an eccentric member rotatable with the fly wheel and initially movable into different adjusted positions upon the fly wheel about an axis which is parallel to the axis of rotation of the shaft and is offset at one side thereof, said eccentric member comprising a crank pin, a connecting rod mounted upon the crank pin, and a ring-shaped counterweight which is rotatable with the fly wheel and is initially movable into different adjusted positions in the ily wheel about an axis which is parallel to the axis of rotation of the shaft, is arranged substantially in a plane including the other two axes and is offset 180 about the axis of rotation ofthe shaft from the axis of rotation of the eccentric member, the axes about which the crank pin and the counterweight are adjusted relatively to the ily wheel being positioned at equal distances from the axis rotation of the shaft.

9. In a variable displacement drive, a powered shaft rotatable about an axis, a fly wheel secured to the shaft and having a cylindrical bore the axis of which extends parallel to and is offsetat one side of the axis ofrotation of the shaft, a crank mounted for angular adjustment in said bore, said ily Wheel having an annular bore centered about an axis which is parallel to the axis of rotation of the shaft and offset 180 from the axis of the cylindrical bore about the axis of r0- tation of the shaft, the axes of the cylindrical and the annular bores being spaced the same distance from the axis of rotation of the shaft, a counterweight mounted for angular adjustment in the annular bore, means for securing the crank and counterweight in their bores to the fly wheel and for releasing the crank and the counter- Weight for adjustment in their bores with relation to the fly Wheel, means for moving the crank into different angularly adjusted positions in the cylindrical bore of the fly wheel, and mechanism responsive to movement of the last-named means for angularly adjusting the counterweight in its annular bore to insure that the fly wheel is balanced for all adjustments of the crank.

10. In a variable displacement drive, mechanism comprising drive shafts rotatable about a common axis and having eccentric portions which internt longitudinally of said axis to cause said shafts to rotate as a unit, an eccentric sleeve mounted upon the eccentric portions, a connecting rod mounted upon said sleeve, and means for moving the sleeve into different adjusted positions circumferentially of said eccentric portions to vary the eccentricity of the sleeve and accordingly the throw of the connecting rod.

11. In a variable displacement drive, bearings, a hollow shaft which is. rotatable in said bearings about an axis and has an eccentric portion provided with an arcuate slot, means for rotating the shaft, an eccentric sleeve mounted for adjustment upon the eccentric portion of the shaft, a member which extends into said hollow shaft and is vconstructed and arranged to be secured to said shaft for rotation therewith or to be released from said shaft for angular adjustment about said axis with relation to the shaft,a pin which is slidable along the arcuate slot of the eccentric portion of the shaft and is operatively connected to said member and to said eccentric sleeve for varying the operative position of the eccentric sleeve upon the eccentric portion of the shaft and accordingly the eccentricity 0f the sleeve in response to the angular movement of said member about said axis in said shaft.

12. In a variable displacement drive, bearings,

a hollow shaft which is rotatable in said bearings about an axis and has an eccentric portion provided with an arcuate slot, means for rotating the shaft, an eccentric sleeve mounted for adjustment upon the eccentric portion of the shaft, `a member which extends into said hollow shaft and is constructed and arranged to be secured to said shaft for rotation therewith or to be released from said shaft for angular adjustment with relation to the shaft about said axis, said .shaft having a pair of eccentric portions which are provided with arcuate slots and which are longitudinally oset from the first-named eccentric portion at opposite ends thereof and are also offset 180 circumferentially from said first-named eccentric portions, counter-weights mounted for j' which is rotatable with the vshaft and is initially adjustable into -diferent voperative positions with relation to the shaft about an axis which is parallel to and offset at one side of vthe axis of rotation of the shaft, .said eccentric havmga .cylindrical driving face .centered about an axis arranged parallel .to the axis `of rotation of the shaft, the axis of said cylindrical driving face including a center of Vmass of the eccentric, a counterweight which is rotatable with the `shaft and is initially adjustable into different Aoperative positions with relation to the shaft about an axis which is parallel to yand lies ina plane including the axis of rotation of .the shaft and the axis about which the eccentric is adjusted, the `axes about which the eccentric and the counterweight are adjusted relatively to the shaft being :positioned `at equal distances .at opposite sides .of the axis .of rotation of the shaft, said fcounterweight having a mass which is equal to the combined mass of the eccentric .and an adjacent half of the .connecting rod and which is positioned Vdiametrically .at :the opposite side ,of the axis of rotation of .the shaft .from -the center of comb'ined .mass of ythe eccentric and an adjacent half of the connecting rod and at the same distance from the axis of rotation 4of the shaft as is positioned the axis of said cylindrical driving face of the `eccentric and accordingly the center vof combined mass .of the eccentric. and `an .adjacent half of the connecting rod, and-means for initially adjusting the eccentric and the countervveight in timed relation about their respective axes to insure that the shaft shall be .balanced irrespective of the throw of the eccentric.

WALLACE M. CUTLER.

HENRY B. GREENOUGH.

EDWIN S. KANT.

REFERENCES CITED The following references are of record in the Ale of this patent:

UNITED STATES PATENTS Number Name Date 1,817,735 Clark Aug. 4, 1931 1,990,184 Greenwald Feb. 5., 1935 2,005,227 Johnson June 18, 1935 2,008,296 Soldan July 16, 1935 2,437,530 Hoopes Mar. 9, 1948 

